Take a look—literally and figuratively—at the people closest to you: the brother who lives two blocks away, the roommate sandwiched next to you on the couch, the girlfriend you spend so much time with, she’s practically an extension of you at this point.

Now, mull this over: There's a 24% chance that right now your personal Facebook page is being hacked by one of them, or soon will be.

Charming, huh? But it’s true, says a new survey from the University of British Columbia, where researchers found that while your profile can be hijacked by some anonymous hacker in, say, Nigeria or China, it's far more common for friends, significant others, or family members to be the ones doing the deed. It’s easy: All they have to do is access your already-logged-in profile from your laptop or phone when you're asleep, at work, or in the shower.

That should make you think twice about not signing out before you walk away.

Using survey results on 1,308 U.S. adult Facebook users, researchers learned that more than 1 out of 5 nosed around on the Facebook accounts of their friends, significant others, and/or family members.  

"It's clearly a widespread practice," study author Wali Ahmed Usmani said in a press release. "Facebook private messages, pictures, or videos are easy targets when the account owner is already logged on and has left their computer or mobile open for viewing."  

But the really fascinating question isn't how they do it—it's why.

As you might imagine, your girlfriend has a different reason for prying than, say, your roommate. For example, she could be trolling your private messages out of jealousy, insecurity, or animosity, the researchers say.

"Jealous snoops generally plan their action and focus on personal messages, accessing the account for 15 minutes or longer," lead study author Ivan Beschastnikh explained. Not that they usually get away with it: “The consequences are significant,” Beschastnikh added. “In many cases, snooping effectively ended the relationship.”

A roommate or buddy, on the other hand, most likely snoops out of curiosity, or for some light-hearted fun. He might change your status to say something ridiculous, like declaring that you're quitting your day job to become a full-time flash mob dancer. Or maybe he just wants to swap your profile picture for something humorous (albeit mortifying), like a shot from that time you swapped clothes with your girlfriend during a ruthless game of Truth or Dare. 

As for why family members would spy? C’mon—they’re family.

Fortunately, though you can't make the people in your life more virtuous, you can take measures to keep their hacking at bay.

"There's no single best defense,” said Beznosov, but “a combination of changing passwords regularly, logging out of your account, and other security practices can definitely help."

And if you have a hunch she's reading your messages on Facebook, another app, or your texts from your phone, read these tips for navigating the awkward situation (without it blowing up in your face).